The present invention relates to an adjustable closure device particularly for ski boots of the rear-entry type.
A strongly felt problem, in known rear-entry ski boots, is that of providing a safe and correct fastening of the quarters and of allowing the skier to walk comfortably when the skis are removed.
Most known ski boot closure devices have a lever adapted to tension one or more cables for closing the quarters; when the lever is opened the quarters are in fact released completely, and the boot may easily slip off when walking.
As a partial solution to this disadvantage, boots are known which have quarter closure means such as transversely arranged bands; the rear quarter then has means which temporarily interact with the shell, and the activation or non-activation of these means allows to free the quarters in their rotation with respect to the axis of pivoting to said shell.
Though better walking is allowed in this manner by virtue of the rotation which the quarters can perform with respect to the shell, it is observed that said quarters are tightly closed, and therefore uncomfortable for the skier.
U.S. Pat. No. 4,581,831 discloses a foot instep closure device which is also adapted to lock the front quarter to the shell in a vorlage position; the device can be released for walking allowing the quarter to rotate with respect to the shell.
Also this device, though, has the above mentioned disadvantages, and it is furthermore structurally very complicated and bulky.
U.S. Pat. No. 4,551,933 discloses a rear-entry ski boot provided with elastic elements interposed between the quarters for the automatic closure thereof consequent to a given voluntary motion which is performed by the skier and is adapted to release the rear quarter from adapted grip means.
This boot also has the previously mentioned disadvantage of being uncomfortable when walking because it can easily slip off.
As regards the feature of tightening the quarters of a boot when flexing the leg, this same Applicant filed a U.S. Pat. application Ser. No. 06/936,865, disclosing a ski boot with a foot securing device the peculiarity whereof consists of the fact that it comprises a traction element for locking the foot inside the shell which is connected to traction means for varying the working length of the traction element inside the shell which can be activated by the oscillation of the quarter with respect to the shell; said traction means are provided with a stop element which can be actuated for the operative disengagement from the oscillation of the quarter, and means are furthermore provided for the removable locking of the loosening of the traction element.
This solution allows to move, by flexing the leg forward a few times, a toothed band toward the tip of the boot and consequently to tension the cables around the heel from the foot instep.
In this solution, however, while the locking devices can be actuated without performing the securing directly with one's hand, there still are the disadvantages related to the skier's easy walking.
U.S. Pat. No. 4,735,004, filed on Apr. 17, 1987, discloses a ski boot which has a device for the closure of the quarters interposed between the front quarter and the shell.
This device, which is also used for the automatic closure of the quarters, however has numerous disadvantages, such as a considerable size and a structural complexity, and significantly alters the styling of the boot.
The considerable structural complication of the device furthermore makes it scarcely reliable and increases its production costs.
Furthermore, the flexibility which can be achieved by means of a resilient element inside the device is minimal and in any case cannot be adjusted.
U.S. Pat. No. 4,499,676 discloses a ski boot having a rocker for locking the rear quarter in a running downhill position. The rocker can be released for straightening the quarter for a walking position.
In this ski boot the quarter fastening means are independent from the rocker and therefore the quarters are not untightened when the rocker is in the walking position.
There is also no further tightening of the quarters, in the skiing position, when the skier tends to flex the leg forwardly.